Why are U.S. gas prices suddenly inching up?

Retail gas prices in the U.S. are creeping up for the first time since September.

According to AAA's latest Monthly Gas Price Report, average gas prices rose for seven straight days last week, after previously falling for a record 123 consecutive days.

"Many drivers are noticing an uptick in gas prices for the first time in months," AAA spokesman Avery Ash said in a statement. "It is typical to see gas prices increase this time of year due to refinery issues, yet hopefully the consumer impact will be less problematic given how low prices are today."

Despite the uptick, a gallon of regular gas across the U.S. costs an average of $2.06, still around $1.22 less per gallon than a year ago. AAA estimates Americans are spending $365 million less per day on gas than they were at this time in 2014.

Several factors are pushing up gas prices. This is the time of year when oil refineries begin to shut down some of their operations for routine maintenance, which can limit production. Meanwhile, a nearly 60 percent decrease in global oil prices since June has also forced many U.S. oil companies to curb production.

Although gas prices are traditionally at seasonal lows this time of year, as many Americans avoid extended driving in the winter weather, AAA says it is "not uncommon" for gas prices to rise by 30 to 50 cents per gallon between the start of February and the middle of spring.

"It is a good bet that most drivers will pay more for gasoline in March than today," Ash noted. "Yet even if gas prices increase as expected, drivers should continue paying at least a dollar less on gasoline than what they spent in recent years during the spring."

AAA does not expect the national price of gas to head above $3 per gallon this year. Citing the continued volatility in world oil markets, the group also says prices at the pump could drop further.